Prince George, Prince Louis delighted royal fans by sharing a charming brotherly exchange during the Trooping the Colour parade on Sunday.
The young royals, aged 7 and 11, were seen departing the Buckingham Palace in a carriage along with their mother, the Princess of Wales, and sister Princess Charlotte.
Meanwhile Prince William and Princess Anne followed the King's coach on horseback as the procession headed towards Horse Guards Parade.
The siblings were among the many royals participating in the grand celebrations for King Charles's official birthday.
As their courage journeyed towards Horse Guards Parade, a keen-eyed lip reader caught a sweet moment between the two royals.
Louis was seen turning to his brother to ask: 'Should I wave?' 'It's up to you,' George was observed responding, the lip reader told The Sun.
Noticing the beautiful weather, George also remarked, 'I can't believe how sunny it is.'
Encouraged by his older brother, Louis then said: Let's do it together.'
However, their close bond was also reflected in their outfits-both brothers sported matching red ties, adding to the sense of unity as they took part in the royal procession. Prince George also debuted a new smart haircut.
While Kate and Charlotte opted for coordinated aqua blue outfits, each accented with sparkling pins.